The ability to integrate information across sensory modalities is essential for successful social and communicative functioning in everyday life. Therefore impaired sensory integration abilities in autism could contribute to the core social and communicative impairments that typify the disorder. Although existing research describes specific sensory integration difficulties in autism, we do not yet know the full extent of the problem. Specifically, it is unclear whether language demands implicit in experimental tasks contribute to documented sensory integration dysfunction. It is also unclear whether study findings have ecological validity, given that tasks have generally involved computer-based stimuli using auditory beeps and flashes. The purpose of the proposed study is to characterize the nature of sensory integration abilities in autism, using a set of complex, ecologically valid stimuli that systematically vary language and social demands across three experiments. This study also tests whether sensory processing abilities have clinical significance and relate to severity of autistic symptoms and level of daily functioning. There are 4 primary aims: 1) To test sensory integration of supplementary gestures and speech, when integration is necessary for understanding (i.e., neither gesture nor speech provide adequate information for reference resolution); 2) to test integration of complementary gestures and speech, when integration supports comprehension but is not necessary for understanding (i.e., speech provides adequate information for reference resolution, but gesture offers supporting content); 3) to test sensory integration in the absence of language and social demands (i.e., integration of musical performance gestures and musical notes); 4) to assess whether there is a relationship between sensory integration abilities and symptom severity and daily functioning. Participants will be 30 individuals with high functioning autism and 30 well matched controls between the ages of 13 and 20. The time course of sensory integration will be measured using eye-tracking methodologies that record visual fixations during computer-based tasks involving gesture, speech, and musical notes. Additional measures of sensory integration abilities will include accuracy scores on video-based tasks, reaction time data, and note duration estimates on music perception tasks involving co-expressive performance gestures. This study is purely translational since it applies psycholinguistic and music perception methodologies to examine underlying impairments in autism. Findings from this study will have direct implications for understanding the core deficits in autism and for designing the next generation of sensory integration therapies. PUBLIC HEALTH RELEVANCE: Project Narrative Autism is a developmental disorder that affects approximately 1 in 150 children and is characterized by a triad of impairments in communication, social interaction, and restricted and repetitive behaviors. Current theories suggest that difficulties integrating information across sensory modalities may be at the heart of the disorder. This proposal describes a series of experiments designed to characterize audio-visual integration of gesture, speech and non-speech sounds in high-functioning autism to test whether these abilities are related to current functioning and expression of symptom severity in autism.